1. Field of Invention
The present invention relates generally to motors and engines.
2. Description of Prior Art
Generators, Motors and engines are well known in prior art. Electric motors, as well as gasoline and diesel engines, are the mainstay of power generation, transportation, and power tools. They range in efficiency from a high of 95% in electric motors to a low of 33% in gasoline engines. However, electric motors require electricity to operate, and electricity costs are steadily rising. Internal combustion engines require hydrocarbon fuels to operate, and they are steadily rising in cost as well. Electric generators are highly efficient as well, but they also require costly fuel sources or hydroelectric energy to create electricity. The Stirling engine is a prior art example of an external combustion thermal differential motorxe2x80x94but it provides relatively low power and is impractical for most modern applications.
A number of xe2x80x9cmemory metalxe2x80x9d actuator and motor designs using bi-metal or Nitinol materials have been disclosed in prior art. Gummin""s U.S. Pat. No. 6,326,707 describes a shape memory alloy actuator using a plurality of wires. Similarly, Richardson""s U.S. Pat. No. 3,940,935 uses a nitinol strand as a spring tensioner. Kutlucinar""s U.S. Pat. No. 6,226,992 discloses a heat converter engine based on shape memory materials that also use a plurality of strands.
The present invention describes unique shape memory material power generating engine technologies which have a minimum of moving parts, require only one shape memory element, an can be scaled to produce tremendous torque with available ambient environmental temperature differentials as fuelxe2x80x94specifically heat, cold, water, and/or sunlight.
The primary objective of the present invention is to provide an efficient, high torque motor which uses sunlight or ambient cold or heat differentials as fuel sources. The invention may also use artificially generated thermal differentials to improve or increase its power output.
The engines in accordance with the present invention transform sunlight, heat, or cold, directly into rotary and linear mechanical force. The invention uses a focusing means to apply ambient temperature differentials to a thermally reactive material retained in a moveable housing. Said thermally reactive material is mounted in contact with a bearing element which either receives or applies directional force from or to said thermally reactive material surface as said surface changes shape in response to said applied ambient temperature differentials.